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Re: [PATCH] Fix PR 51505
- From: Eric Botcazou <ebotcazou at adacore dot com>
- To: Andrey Belevantsev <abel at ispras dot ru>
- Cc: gcc-patches at gcc dot gnu dot org, Paolo Bonzini <bonzini at gnu dot org>
- Date: Sun, 29 Jan 2012 14:02:24 +0100
- Subject: Re: [PATCH] Fix PR 51505
- References: <4F16F628.8030002@ispras.ru>
> As discussed in Bugzilla, this is the patch implementing Paolo's suggestion
> of killing REG_EQUAL/REG_EQUIV notes from df_kill_notes. The code assumes
> there is at most one such note per insn.
That's wrong though and wreaks havoc during reload, e.g.:
(insn 169 60 62 4 (set (reg:TF 158)
(mem/c:TF (plus:SI (reg/f:SI 101 %sfp)
(const_int -16 [0xfffffffffffffff0])) [3 S16 A64]))
960513-1.c:13 97 {*movtf_insn_sp32}
(expr_list:REG_EQUIV (mem/c:TF (plus:SI (reg/f:SI 101 %sfp)
(const_int -16 [0xfffffffffffffff0])) [3 S16 A64])
(expr_list:REG_EQUAL (mult:TF (reg/v:TF 110 [ d ])
(reg:TF 154))
(nil))))
because the REG_EQUIV note disappears behind reload's back and it isn't
prepared for that. This is the cause of the following regression on SPARC:
FAIL: gcc.c-torture/execute/960513-1.c execution, -Os
--
Eric Botcazou